Racal Instruments 3155, User Manual

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User Manual 3155
ArbConnection 3-49
tion generates a sine waveform. If you change the offset setting in
the Offset field and press the Adjust key, the waveform offsets im-
mediately without changing the equation. You can also change the
amplitude, or both amplitude and offset. If you check the Manual op-
tion, click on the Adjust button for the Amplitude and Offset parame-
ters to take effect. The Adjust button name changes to Restore and
back to Adjust if you click on it again. If you check the Auto option,
your waveform is created automatically with the new Amplitude and
Offset setting.
Equation
Use the Equation field to write your equations. Equation syntax and
conventions are discussed below.
Control Buttons
There are five control buttons at the right corner of the dialog box.
Use the Preview button to preview an image of your equation, or use
the OK button to place your waveform on the waveform screen and
to leave the dialog box. The Browse button opens the waveform
browser so you can search for pre-stored waveforms to add to your
equation. The Operands button expands the dialog box to show all of
the operands available for use in the Equation Editor. The Cancel
button removes the dialog box from the screen and discards of any
waveforms previewed with the Equation Editor.
Writing Equations
The Equation Editor converts your mathematical expressions into
waveform coordinates. As you probably already know, waveforms
are made of vertical samples. The number of samples in your wave-
form is determined by the wavelength parameter. For example, if you
have 1024 horizontal points, your equation is computed along 1024
points as a function of the vertical scale. Each vertical sample is
computed separately and placed along the horizontal axis. The
points are graphically connected to form a continuous waveform.
However, if you zoom in on a waveform line, you’ll see that the points
are connected like a staircase. In reality, the 3155 generates its
waveforms exactly as shown on the screen however, if the waveform
has many horizontal points, the steps are hard to see.
Equations are always computed as a function of the vertical (Ampli-
tude) axis therefore the left side of your equation will always look as
Ampl(p)=, where “p” is the amplitude function of waveform points.
You can write equations with up to 256 characters. If the equation is
too long to fit in the visible field, parts to the left or right scroll out of
view.